This invention relates to fatty alcohol ethoxylates of the formula in which m represents average values from 8.0 to 13.0 and n represents average values from 6.0 to 17.0, that are highly suitable for use as penetrants for insecticidally active neonicotinyls when employed in amounts such that they are present in the commercial formulations in concentrations from 0.1 to 30% by weight and such that the weight ratio of neonicotinyl to fatty alcohol ethoxylate is from 1:0.1 to 1:2.0.